This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Mouse olfaction is mediated by ~1000 odorant receptors (ORs) expressed in the cilia of olfactory sensory neurons (OSNs). It is known that ORs are also expressed in the axons of OSNs and that ORs help mediate axon pathfinding during development. To understand the role of ORs in axon pathfinding, antibodies to an OR was used to immunoprecipitate OR protein complexes from various olfactory tissues. These tissues include olfactory epithelium (OSN cilia/cell body) and olfactory bulb (OSN axons) from adult and neonatal animals. By comparing samples from OB to those from the OE, we hope to gain insight into the mechanism of OR-directed axonal targeting.